Filling bobbin adapted to detect the impending exhaustion of the thread wound up thereon



Dec. 22, 1959 E. REDAELLI 2,918,225

FILLING BOBBIN ADAPTED TO DETECT THE IMPENDING EXHAUSTION OF THE THREAD WOUND up THEREON Filed Sept. 26, 1957 Edoarda wgdamui FILLING BOBBIN ADAPTED TO DETECT THE INI- PENDING EXHAUSTION OF THE THREAD WOUND UP THEREON Edoardo Redaelli, Milan, Italy Application September 26, 1957, Serial No. 686,422

Claims. (Cl. 242-36) It isan object of the present invention to provide a bobbin for yarns, in particular a filling bobbin for weaving shuttles, but susceptible also of other uses, which is adapted to reveal the impending exhaustion of the .yarn that is being wound off the same. Said bobbin comprises two parts movable axially with respect to each other, urged towards one of the extreme positions of said mutual displacement by the action of an elastic means, and adapted to be retained in its other position against the action of said elastic means by a certain number of windings of thread wound up the bobbin. 4

For instance the bobbin may be constituted by two parts mounted telescopically slidable for a certain space upon one another and containing a spring that tends to keep them in elongated position, whence if the yarn is wound up the bobbin is forcibly held in retracted position, the yarn keeping the bobbin in this latter position; on unwinding then the yarn, when it is near to being exhausted, the few windings of yarn that remain are no longer sufficient to contrast the action of the spring, which causes elongation of the bobbin. The elongated position of the bobbin, therefore, indicates the impeding exhaustion of the yarn thereon and may be utilized to actuate signalling devices, devices for stopping the machine wherewith the bobbin is assembled or devices for the automatical replacement of the bobbin.

Another preferred characteristic of the instant invention consists in providing means for tieing up with each other the two parts constituting the bobbin, being adapted to prevent said two parts, when exhaustion of the yarn is impending, from moving by mutual torsion so as to avoid twisting of the last windings wound upon the bobbin and sometimes even breakage of said windings, and adapted to enable said parts to perform normal axial mutual movement.

According to one improved embodiment of the invention, particularly adapted for bobbins rotatable on a fixed axis, the mutual movement of the two parts is such as not to cause any variations of friction in rotation and, therefore, in that improved embodiment one of the two parts is guided completely on the other one and the spring that tends to take them away from each other can expand completely before the elongation of the bobbin becomes such as to cause a thrust upon the flanges of the axis which hold axially the two parts of the bobbin. The accompanying drawing shows diagrammatically by way of example a bobbin according to the invention.

Fig. 1 is an axial section of the bare bobbin;

Fig. 2 is a cross-section of the bobbin shown in Fig. 1;

Figs. 3 and 4 are respectively a lateral view and a terminal view of the loaded bobbin and Figs. 5 and 6 represent the bobbin at a time near to the exhaustion of the thread, in analogous views.

In the embodiment represented, the bobbin, which is of the kind particularly suited for ribbon looms, comprises a spindle 1 provided with flanges 2 and 3, where- .States. Pat

on there are mounted loose two pieces 4 and 5. The piece 5 extends to the whole length confined by said flanges 2 and 3 and has in longitudinal section three portions of different cross-section, indicated with 5, 5' and 5" respectively. On the end head of the portion 5 there is provided a groove 7 wherein the flange 3 of the spindle 1 is housed.

The piece 4 is tubular and is mounted slidably under the action of a spring at the portions 5' and 5" of the piece 5; the length of the spring 8 in freely expanded position is smaller than the maximum length of the annular space containing it, in such' a way as never to cause any axial pressure upon the flanges 3 and 6.

The piece 4 is provided with a' radial projection 12 engaged in a longitudinal radial groove 13 provided in the portion 5' of the piece 5, in such a way as to prevent the pieces 4 and 5 from performing a torsional mutual movement and to enable them to perform the normal axial mutual movement. I p

When the parts 4 and 5 draw closer to each other, the bobbin retracts becoming shorter as indicated in Figure 3, which shows it already loaded with yarn 10; the latter retains the bobbin in said position, while when it is unwound and reduced to few windings as indicated diagrammatically in Figure 5, the spring 8 prevails and the bobbin elongates again.

In the drawing there is indicated a feeler member 11 having one end shaped like a fork and adapted to move transversally with respect to the spindle 1, which is of course supported in use by special supporting means not represented. If the bobbin is loaded, the member 11 can advance and surround the spindle 1 as far as the position indicated in Figures 3 and 4, while if the bobbin is nearly loadless, said member 11 is stopped by the piece 4 (see Figs. 5 and 6). j

The member 11 or other equivalent member, therefore, is in condition for revealing the impending exhaustion of the thread on the bobbin; it can thus actuate in any manner known per se, a signalling mechanism or a mechanical movement as may be desired to intervene as a consequence of the impending lack of thread.

I claim:

1. A bobbin for textile machines which is capable of revealing the impending exhaustion of a thread wound thereon, comprising a spindle, two coaxial cylindrical elements mounted on said spindle for free rotation thereon, one of said elements being slidable axially with respect to the other element, and a spring constantly urging said elements apart, the convolutions of thread wound on the bobbin acting to hold said elements in predetermined axial relation to one another against the resistance of said spring as long as there remain a suiticient number of thread convolutions wound on the bobbin, whereby when the convolutions of thread wound on the bobbin have been reduced below said number said elements will be moved apart to indicate impending exhaustion of the thread.

2. A bobbin for textile machines which is capable of revealing the impending exhaustion of a thread wound thereon, comprising a spindle having thereon two axiallyspaced flanges, a first element mounted on said spindle for free rotation thereon between said flanges, said element having a cylindrical portion along part of its length which is one diameter and a portion along another part of its length which is of smaller diameter than said cylindrical portion, a tubular element mounted on the smaller diameter portion of said first element for sliding movement axially thereon, said tubular element having an outer cylindrical surface which is of the same diameter as said cylindrical portion, and a spring interposed between said two elements and constantly urging said tubular element to slide axially on said first element axially away from said cylindrical portion thereof.

3. A bobbin for textile machines which is capable of revealing the impending exhaustion of a thread wound thereon, comprising a spindle, two coaxial cylindrical elements mounted on said spindle for free rotation thereon, one of said elements being axially slidable relative to the other, means for preventing relative rotation between said elements, a spring constantly urging said elements axially apart, -said elements being held against relative movement apart by said spring by the convolutions of thread wound on said bobbin as long as there remains a sufficient number of convolutions on said qb in- 4 4. A bobbin for textile machines which is capable of revealing the impending exhaustion of a thread wound thereon, comprising a spindle having axially spaced flanges thereon, a first element mounted for free rotation on said spindle between said flanges and comprising a cylindrical portion and a second portion whose diameter is smaller than the diameter of said cylindrical portion, a tubular element having a cylindrical outer surface whose diameter is the same as that of said cylinr drical portion, said tubular element being mounted on 4 said second portion for free axial sliding movement thereon, means preventing rotation of said tubular element with respect to said first element, and a spring urging said tubular element to slide on said second portion axially away from said cylindrical portion.

5. A bobbin for textile machines as claimed in claim 4 in which said spring is a coil spring, and is contained in an axially expandable annular space between said tubular element and said second portion, and in its freelyexpanded position has a length less than the axial length of said annular space when said elements bear against said flanges.

References Cited in the file of this patent UNITED STATES PATENTS 1,502,413 Turner July 22, 1924 2,270,645 Briggs Jan. 20, 1942 2,492,728 Balz Dec. 27, 1949 2 ,571,321 Wettley Oct. 16,1951

2,753,209 Klasky July 3, 1956 FOREIGN PATENTS 290,566 Great Britain 1929 

